Immunomodulatory approaches to the treatment of infections

Imunološki sustav nudi široki izbor potencijalnih ciljnih mjesta za modulaciju kod liječenja infektivnih bolesti. Raspoložive mogućnosti dozvoljavaju i profilaktičku i terapijsku imunomodulaciju za suportivno i direkto liječenje infekcija. Odgovarajuća prehrana koja sadrži biljne polifenole, osobito one iz voća, te mikronutrijente kao što su selen i cink, uz redovitu umjerenu fizičku aktivnost pomaže u održavanju učinkovite obrane domaćina od blagih do umjereno teških infekcija. Ovakva nadopuna prehrani obično je prijeko potrebna kod životno ugroženih bolesnika, tako neki biljni pripravci mogu smanjiti težinu i/ili duljinu trajanja infekcija gornjih dišnih putova. Primjena probiotika također potpomaže imunološkoj obrani gastrointestinalnog trakta. Nekoliko antibiotika, prvenstveno makrolidi i tetraciklini, osim antibakterijskog djelovanja imaju i imunomodulatorna i/ili protuupalna svojstva koja potpomažu uništavanju bakterija i/ili štite tkivo od "bystander" ozljeda. Također, mogu biti korisni i u prevenciji tzv. "citokinske oluje" izazvane virusima. Imunoglobulini, nekoliko rekombinantnih humanih citokina te različiti agonisti receptora sličnih Tollu zbog svog visoko specifičnog djelovanja na određene imunološke procese, posredovanog receptorima učinkoviti su kod mnogih infekcija. Vrlo je vjerojatno da bi razvoj novih imunomodulatora koji ciljaju specifične receptore mogao zamijeniti primjenu nespecifičnih modulatora prirođene imunosti kao pomoći pri obrani domaćina od infekcije.The immune system offers a wide variety of potential targets for modulation in the treatment of infectious diseases. Available possibilities permit both prophylactic and therapeutic immunomodulation for supportive and direct treatment of infections. In addition to regular moderate exercise, an adequate diet containing plant polyphenols, particularly from fruit, and micronutrients such as selenium and zinc helps maintain effective host defence against mild to moderate infections. Supplementation with these dietary constituents is usually necessary in critically ill patients and like some standardized phytopharmaceuticals, may also reduce the severity and/or duration of upper airways infections. Administration of probiotics also promotes gastrointestinal immune defence. Several antibiotics, especially the macrolides and tetracyclines, possess in addition to their antibacterial actions, immunomodulatory and/or anti-inflammatory properties which facilitate bacterial killing and/or protect tissue from bystander injury. They may also be useful in prevention of the virally-induced cytokine storm. Immunoglobulins, several recombinant human cytokines and selective agonists of Toll-like receptors are effective against many infections in their own right because of highly specific receptor-mediated actions on defined immune processes. The development of novel receptor-targeted immunomodulators is likely to replace the use of non-specific modulators of innate immunity in promoting host defence during infection

Kinetic characterization of selective peroxisome-proliferator-activated receptor gamma modulators in vitro

Background: The ligand-activated transcription factor, peroxisome-proliferator-activated receptor gamma (PPARγ), has been shown to play an essential role in immunosuppression during sepsis. PPARγ is upregulated in T cells of septic patients, sensitizing these cells to PPARγ-dependent apoptosis and thus contributing to T-cell depletion. In the polymicrobial cecum ligation and puncture (CLP) sepsis model in mice, both T-cell-specific gene knockout (Lck-Cre PPARγfl/fl) and systemic pharmacological PPARγ antagonism by GW9662 improved survival. Because GW9662 was only effective when applied 3 hours after CLP, we were interested to extend this time frame. For this reason we characterized the kinetics of SPPARγMs when administered before or in combination with the agonist thiazolidinedione, rosiglitazone. Methods: A PPARγ-dependent transactivation assay was used in HEK293T cells. It is based on the vector pFA-PPARγ-LBD-GAL4-DBD encoding the hybrid protein PPARγ-LBD-GAL4-DBD and the reporter vector pFR-Luc, carrying a GAL4-responsive element in front of the Firefly luciferase gene. These two vectors were co-transfected, in combination with a control vector encoding Renilla luciferase (pRL-CMV) to normalize Firefly luciferase activity for transfection efficiency. Following transfection, cells were incubated with the SPPARγMs F-MOC and MCC-555 and the PPARγ antagonist GW9662 for different times (2 to 48 hours) and at increasing doses (0.01 to 10 μM), with or without rosiglitazone (0.01 to 10 μM). Transactivation was analyzed using a 96-well plate format. Results: Rosiglitazone transactivated PPARγ in a time-dependent and dose-dependent manner, the response gradually increasing to a maximum at 48 hours with 10 μM. Low concentrations (0.01 to 0.1 μM) of SPPARγMs F-MOC and MCC-555 and the PPARγ antagonist GW9662 all exerted dose-independent antagonistic effects at an early incubation time point (2 hours). From 10 hours onwards, MCC-555 and GW9662, given alone, both exerted PPARγ agonistic effects, MCC-555 in parallel to responses to rosiglitazone, but GW9662 with characteristics of partial antagonism. F-MOC showed no dose-dependent effect at any concentration at later time points. Only GW9662 (1 to 10 μM) was able to inhibit rosiglitazone (0.1 to 1 μM)-induced PPARγ transactivation after 10 hours. Conclusion: Our kinetic analysis reveals clear differences in the modulatory characteristics of PPARγ inhibitors, with previously unreported early inhibitory effects and late agonistic or partial agonistic activity. New SPPARγMs with extended inhibitory activity may prove useful in the therapy of sepsis

Editorial

Terapeutici, infekcija i imunomodulacijaTherapeutics, infection and immunomodulatio

From Cancer to Immune-Mediated Diseases and Tolerance Induction: Lessons Learned From Immune Oncology and Classical Anti-cancer Treatment

Success in cancer treatment over the last four decades has ranged from improvements in classical drug therapy to immune oncology. Anti-cancer drugs have also often proven beneficial for the treatment of inflammatory and autoimmune diseases. In this review, we report on challenging examples that bridge between treatment of cancer and immune-mediated diseases, addressing mechanisms and experimental models as well as clinical investigations. Patient-derived tumor xenograft (PDX) (humanized) mouse models represent useful tools for preclinical evaluation of new therapies and biomarker identification. However, new developments using human ex vivo approaches modeling cancer, for example in microfluidic human organs-on-chips, promise to identify key molecular, cellular and immunological features of human cancer progression in a fully human setting. Classical drugs which bridge the gap, for instance, include cytotoxic drugs, proteasome inhibitors, PI3K/mTOR inhibitors and metabolic inhibitors. Biologicals developed for cancer therapy have also shown efficacy in the treatment of autoimmune diseases. In immune oncology, redirected chimeric antigen receptor (CAR) T cells have achieved spectacular remissions in refractory B cell leukemia and lymphoma and are currently under development for tolerance induction using cell-based therapies such as CAR Tregs or NK cells. Finally, a brief outline will be given of the lessons learned from bridging cancer and autoimmune diseases as well as tolerance induction

Flow cytometry-based FRET identifies binding intensities in PPAR[gamma]1 protein-protein interactions in living cells

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PEERS - an open science “Platform for the Exchange of Experimental Research Standards” in biomedicine

Funding The PEERS Consortium is currently funded by Cohen Veterans Bioscience Ltd and grants COH-0011 from Steven A. Cohen. Acknowledgements We would like to thank IJsbrand Jan Aalbersberg, Natasja de Bruin, Philippe Chamiot-Clerc, Anja Gilis, Lieve Heylen, Martine Hofmann, Patricia Kabitzke, Isabel Lefevre, Janko Samardzic, Susanne Schiffmann and Guido Steiner for their valuable input and discussions during the conceptualization of PEERS and the initial phase of the project.Peer reviewedPublisher PD

Comparison of systemic inflammatory and hematology parameters in normal C57BI/6 and genetically diabetic db/db mice during local wound repair

Uvod: Upala je početni odgovor domaćina na ozljedu. Ona nije ograničena samo na mjesto rane, nego izaziva sustavne promjene uključujući raznovrsne fiziološke i biokemijske promjene koje se skupno nazivaju odgovorom akutne faze. Ove se promjene nastavljaju tijekom rješavanja upale i procesa cijeljenja rane. U ovom ispitivanju smo usporedili serumski amiloid A protein (SAA), hematološke parametre (ukupna bijela krvna slika, postotak neutrofila i lim-focita) te koncentracije interferona-gama (IFN-γ) u serumu tijekom cijeljenja neokludirane, ekscizijske kožne rane u punoj debljini kod genetski dijabetičnih db/db miševa i nedijabetičnih C57Bl/6 miševa iz istoga legla. Materijal i metode: Područje rane izazvane „punch" biopsijom (promjera 8 mm) kod svakog je miša analizirano planimetrijski uz računalnu potporu. Trećeg, 6., 9. i 13. dana od ranjavanja SAA i IFN-g mjereni su u plazmi testovima ELISA, a hematološki parametri u punoj krvi na automatskom hematološkom analizatoru Sysmex SF 3000. Rezultati: Šestog i devetog dana jasno je zabilježeno kašnjenje u zatvaranju rane kod db/db miševa u usporedbi sa zdravim miševima. Ukupna bijela krvna slika bila je značajno viša u db/db miševa 9. i 13. dana. Kroz čitavo razdoblje obnove rane, diferencijalni broj neutrofila bio je viši, a broj limfocita niži kod db/db miševa u usporedbi s C57Bl/6 miševima. Vršne koncentracije SAA zabilježene su 3. dana kod C57Bl/6 miševa i db/db miševa (368,7 mg/L odnosno 173,5 mg/L), s težnjom prema nižim vrijednostima kod db/db miševa. Razine IFN-γ bile su značajno više (P < 0,05) 9. i 13. dana kod db/db miševa (75,3 pg/mLodnosno 89,9 pg/mL) u usporedbi s razinama kod C57Bl/6 miševa (66,6 pg/mL odnosno 57,2 pg/mL). Zaljučak: Lokalni proces tkivne regeneracije kod miševa nakon lokalne kožne ozljede uzrokuje sustavne promjene u perifernoj krvi. Niti određivanje koncentracije SAA niti IFN-γ nije se moglo rabiti za motrenje dinamike cijeljenja rane u ovim vremenskim točkama.Introduction: Inflammation is the initial host response to injury. It is not only localized to the wound site but also causes systemic changes, including a variety of physiological and biochemical changes collectively called the acute phase response. These changes continue during the resolution of inflammation and the wound healing process. In this study we compared serum amyloid A protein (SAA), hematological parameters (total white blood cell count, neutrophil and lymphocyte percentage) and interferon-gamma (IFN-γ) concentrations in serum during healing of non-occluded, excisional, full-thickness dermal wounds in genetically diabetic db/db mice and non-diabetic C57Bl/6 littermates. Materials and Methods: Area of a punch biopsy (8 mm in diameter) wound in each mouse was analyzed by computer-assisted planimetry. On days 3,6, 9 and 13 after wounding, SAA and IFN-γ were measured in plasma by ELISA assays and hematological parameters in whole blood by SysmexSF 3000 automatic hematology analyzer. Results: A delay in the closure of wounds in db/db in comparison to normal mice was clearly seen on days 6 and 9. Total white blood cell count was significantly higher on days 9 and 13 in db/db mice. Differential neutrophil counts were higher and lymphocyte counts lower in db/db mice in comparison to C57BL/6 mice throughout the wound repair period. Peak SAA concentrations were seen on day 3 in C57Bl/6 and db/db mice (368.7 mg/L and 173.5 mg/L, respectively), but tended to be lower in db/db mice. IFN-γ levels were significantly higher (P < 0.05) on days 9 and 13 in db/db (75.3 pg/mL and 89.9 pg/mL, respectively) in comparison to those in C57Bl/6 mice (66.6 pg/mL and 57.2 pg/mL, respectively). Conclusion. The local tissue regeneration process in mice after local skin injury causes systemic changes in peripheral blood. Determination of neither SAA nor IFN-γ concentrations could be used to monitor wound healing dynamics at these time points

Discovery of Protein-Protein Interaction Inhibitors by Integrating Protein Engineering and Chemical Screening Platforms

Protein-protein interactions (PPIs) govern intracellular life, and identification of PPI inhibitors is challenging. Roadblocks in assay development stemming from weak binding affinities of natural PPIs impede progress in this field. We postulated that enhancing binding affinity of natural PPIs via protein engineering will aid assay development and hit discovery. This proof-of-principle study targets PPI between linear ubiquitin chains and NEMO UBAN domain, which activates NF-κB signaling. Using phage display, we generated ubiquitin variants that bind to the functional UBAN epitope with high affinity, act as competitive inhibitors, and structurally maintain the existing PPI interface. When utilized in assay development, variants enable generation of robust cell-based assays for chemical screening. Top compounds identified using this approach directly bind to UBAN and dampen NF-κB signaling. This study illustrates advantages of integrating protein engineering and chemical screening in hit identification, a development that we anticipate will have wide application in drug discovery

IL-38 Ameliorates Skin Inflammation and Limits IL-17 Production from γδ T Cells

Summary: Interleukin-38 (IL-38) is a cytokine of the IL-1 family with a role in chronic inflammation. However, its main cellular targets and receptors remain obscure. IL-38 is highly expressed in the skin and downregulated in psoriasis patients. We report an investigation in cellular targets of IL-38 during the progression of imiquimod-induced psoriasis. In this model, IL-38 knockout (IL-38 KO) mice show delayed disease resolution with exacerbated IL-17-mediated inflammation, which is reversed by the administration of mature IL-38 or γδ T cell-receptor-blocking antibodies. Mechanistically, X-linked IL-1 receptor accessory protein-like 1 (IL1RAPL1) is upregulated upon γδ T cell activation to feedforward-amplify IL-17 production and is required for IL-38 to suppress γδ T cell IL-17 production. Accordingly, psoriatic IL1RAPL1 KO mice show reduced inflammation and IL-17 production by γδ T cells. Our findings indicate a role for IL-38 in the regulation of γδ T cell activation through IL1RAPL1, with consequences for auto-inflammatory disease. : Han et al. report that genetic depletion of IL-38 in mice delays the resolution of imiquimod-induced psoriasis by increasing the production of the inflammatory cytokine IL-17A by skin-infiltrating T cells. Depleting these T cells or the receptor that is targeted by IL-38 reduces psoriatic skin inflammation. Keywords: IL-38, IL1RAPL1, IL-17, γδ T cells, psoriasis, inflammatio